The present invention relates to an aromatic polyester/aromatic polycarbonate resin composition which is excellent in bending resistance and solvent resistance.
Generally, aromatic polyesters are thermoplastic resins excellent in properties such as oxidation resistance and solvent resistance, and the molten-molded products thereof are widely used as products having good physical and mechanical properties. These resins, however, have a high crystallinity, so that when they are molded by injection molding, etc., the dimensional stability is poor. In order to remedy this defect, investigation on adding an aromatic polycarbonate which has a good dimensional stability to an aromatic polyester has been made.
On the other hand, aromatic polycarbonate resins, particularly, bisphenol A polycarbonates, are poor in solvent resistance and moldability. Accordingly, attempts to add an aromatic polyester to an aromatic polyester have been made (e.g., Japanese Patent Publication No. 36-14035 (1961)). When an aromatic polycarbonate is mixed with an aromatic polyester, a dimensional stability is provided for the aromatic polyester. The resin composition obtained in this way, however, has insufficient bending resistance and when an injection molded product for a member having a hinge portion is produced from this resin composition, a crack is disadvantageously produced at the hinge portion due to repetition of folding.
Although the solvent resistance and the moldability of an aromatic polycarbonate are improved to some extent by adding an aromatic polyester thereto, but they are still unsatisfactory.
As a result of studies undertaken by the present inventors with a view to eliminating the above-described problems in the prior art, it has been found that a composition obtained by mixing a reaction product of an unsaturated carboxylic acid or a derivative thereof and an .alpha.-olefin having a molecular weight of 40 to 2,000 with an aromatic polyester/aromatic polycarbonate resin composition can provide a molded product having not only a good dimensional stability but also improved bending resistance and solvent resistance. The present invention has been achieved on the basis of this finding.